Stimulation of wound healing by the immunomodulator LS-2616 (Linomide)

LS-2616 (Linomide), a quinoline-3-carboxamide, is an immunomodulator that has been suggested to act on macrophage-like cells. Based on a hypothesis that LS-2616 would stimulate macrophages in the wound and affect the healing process, the effects of LS-2616 on developing granulation tissue were evaluated using a wound model in rats. Subcutaneously implanted cylindrical cellulose sponges were used as an inductive matrix for the ingrowth of granulation tissue. LS-2616 was continuously present at a concentration of 1.2 mg/ml in the drinking water either for 7 days before implantation or starting at the implantation of sponges. Seven days after implantation LS-2616 treatment increased the mean amounts of nitrogen and collagen hydroxyproline over the control level [+20% (p < 0.05) and +59% (p < 0.05), respectively]. The effect was less pronounced in the rats receiving LS-2616 in advance [+7% (NS) and +38% (p < 0.05), respectively]. The mean amounts of nucleic acids and proteoglycans tended to decrease in the rats receiving LS-2616 in advance compared to the control rats [-12% to 13% (NS) and -25% (p < 0.05), respectively]. It was concluded that continuous oral administration of LS-2616 enhanced wound repair in the rat. This immunoenhancement of wound healing results in increased accumulation of collagen.